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From: Aapo Vienamo <aapo.vienamo@linux.intel.com>
To: Michael Walle <michael@walle.cc>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	linux-mtd@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Aapo Vienamo <aapo.vienamo@linux.intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH 2/2] mtd: core: Don't fail mtd_device_parse_register() if OTP is unsupported
Date: Thu,  7 Mar 2024 15:04:18 +0200
Message-ID: <20240307130418.3131898-3-aapo.vienamo@linux.intel.com>
In-Reply-To: <20240307130418.3131898-1-aapo.vienamo@linux.intel.com>
References: <20240307130418.3131898-1-aapo.vienamo@linux.intel.com>
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Handle the case where -EOPNOTSUPP is returned from OTP driver.

This addresses an issue that occurs with the Intel SPI flash controller,
which has a limited supported opcode set. Whilst the OTP functionality
is not available due to this restriction, other parts of the MTD
functionality of the device are intact. This change allows the driver
to gracefully handle the restriction by allowing the supported
functionality to remain available instead of failing the probe
altogether.

Signed-off-by: Aapo Vienamo <aapo.vienamo@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/mtd/mtdcore.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c365c97e7232..1cfc8bb5187d 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1054,8 +1054,14 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
 
 	mtd_set_dev_defaults(mtd);
 
+	/*
+	 * Don't abort MTD init if OTP functionality is unsupported. The
+	 * cleanup of the OTP init is contained within mtd_otp_nvmem_add().
+	 * Omitting goto out here is safe since the cleanup code there
+	 * should be no-ops.
+	 */
 	ret = mtd_otp_nvmem_add(mtd);
-	if (ret)
+	if (ret && ret != -EOPNOTSUPP)
 		goto out;
 
 	if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
-- 
2.41.0